The invention claimed in each of the claims of the present application relates to a method for molding module electronic devices each capable of being easily coupled with and removed from a connector provided on an electronic apparatus to be used for, for example, an information recording medium in which data are stored and from which the data are read, an apparatus for molding on which the method is carried out or a module electronic device molded by the method.
There has been already spread several module electronic devices, each of which is capable of being easily coupled with and removed from a connector provided on an electronic apparatus, such as a personal computer, an information recording and reproducing apparatus or the like, to be used for, for example, an information recording medium of the card type which operates under the condition of electrical connection with the electronic apparatus. One type of the previously proposed module electronic devices is so constituted as to shown in FIGS. 1 and 2, for example.
Referring to FIGS. 1 and 2, one example of the previous module electronic devices is shown to be a module electronic device 1. The module electronic device 1 has a base board 3 and upper and lower covers 15 and 17 each made of resin. The base board 3 is put between the upper and lower covers 15 and 17. Several circuit elements 14 are mounted on the base board 3 and further plural terminals 2 and plural isolating ribs 5 are fixed to be arranged on the base board 3.
In the module electronic device 1, the upper and lower covers 15 and 17 are adhered to each other to be combined with the base board 3. The plural terminals 2 are so arranged in the direction of width of the base board 3 that an end face 2a of each of the terminals 2 is identical in position with an end face 3a of the base board 3. A part of the base board 3 on which the plural terminals 2 are provided is exposed to the outside of the upper cover 15. The lower cover 17 extends over the end face 2a of each of the terminals 2 and the end face 3a of the base board 3 to form a fringe portion 17a of the lower cover 17 positioned at the outside of the end faces 2a and 3a. 
When the module electronic device 1 having the upper and lower covers 15 and 17 as described above is produced, it is necessary such relatively troublesome works as to combine, with the greatest care, the upper and lower covers 15 and 17 with the basic board 3 on which the circuit elements 14 are mounted and the terminals 2 and ribs 5 are arranged and to adhere the upper and lower covers 15 and 17 to each other. These works for combining the upper and lower covers 15 and 17 with the basic board 3 and adhering the upper and lower covers 15 and 17 to each other prevent the module electronic device 1 from being miniaturized and therefore it is feared that the module electronic device 1 can not be sufficiently small-sized.
Accordingly, in order to avoid the disadvantages mentioned above, it is considered to obtain the module electronic device 1, which is capable of being coupled with and removed from the connector provided on the electronic apparatus, as a resin-molding which is produced by means of a molding machine having a pair of upper and lower molds 6 and 7 as shown in FIG. 3.
In FIG. 3, the upper and lower molds 6 and 7 which are put in a mutually contacting condition are shown and a base board 3′ on which several circuit elements (not shown) are mounted and plural terminals and plural ribs (not shown) are arranged in the same manner as the base board 3 shown in FIG. 1 is put in a molding space between the upper and lower molds 6 and 7. The molding space between the upper and lower molds 6 and 7 is formed to have its shape identical substantially with the external shape of the module electronic device 1.
Under the condition in which the base board 3′ is put in the molding space with terminals 2′ (only one of the terminals 2′ is shown in FIG. 3) facing the upper mold 6, dissolved resin 8 is injected with high pressure into the molding space between the upper and lower molds 6 and 7 from a resin injecting portion (not shown in the figures) provided at the outside of the upper and lower molds 6 and 7 so that the molding space is filled with the dissolved resin 8. The dissolved resin 8 injected into the molding space covers the base board 3′ with the terminals 2′ on the base board 3′ exposed to the outside of the dissolved resin 8. Then, when the dissolved resin 8 injected into the molding space has been cooled and solidified, the upper and lower molds 6 and 7 are removed from each other, so that a module electronic device is obtained as a resin-molding from the molding machine which is provided with the upper and lower molds 6 and 7.
The module electronic device thus obtained as the resin-molding has upper and lower parts corresponding respectively to the upper and lower covers 15 and 17 of the module electronic device 1 shown in FIG. 1 though it is formed in a body with the solidified resin. The lower part of the module electronic device is provided with a fringe portion which is similar to the fringe portion 17a of the lower cover 17 of the module electronic device 1 shown in FIG. 1. Further, in the module electronic device obtained from the molding machine having the upper and lower molds 6 and 7, the end face 2a′ of each of the terminals 2′ and the end face 3a′ of the base board 3′ are in contact with the fringe portion of the lower part in the similar manner as those in the module electronic device 1 shown in FIG. 1.
It is possible to mold two or more of the above mentioned module electronic device at a time by means of plural pairs of upper and lower molds and therefore the production cost of module electronic device can be reduced.
When the module electronic device is produced by means of the molding machine having the upper and lower molds 6 and 7 as mentioned above, it is desired that the upper and lower molds 6 and 7 forming the molding space and the base board 3′ as a molding raw material are in high processing accuracy so that the module electronic device is molded into a predetermined shape with high accuracy and the plural terminals 2′ are fixed in position of arrangement on the base board 3′ of the module electronic device.
However, the processing accuracy of each of the upper and lower molds 6 and 7 and the base board 3′ has its limit as a matter of course and each of the upper and lower molds 6 and 7 and the base board 3′ has a predetermined dimensional tolerance. In the case where a resin-molding process is carried out under the condition in which there is a positional difference within the dimensional tolerance between each of the upper and lower molds 6 and 7 and the base board 3′, it is feared that the module electronic device obtained as the resin-molding is undesirably provided with an unnecessary resin wall 11 formed on or in close vicinity of the terminals 2′ as shown in FIG. 4 or FIG. 5.
In the case of the unnecessary resin wall 11 shown in FIG. 4, when the dissolved resin 8 injected into the molding space formed between the upper and lower molds 6 and 7 solidifies to form upper and lower parts 9 and 10 of the module electronic device in a body, the dissolved resin 8 spreads to the terminals 2′ on the base board 3′ through a very small gap between the upper mold 6 and the terminals 2′ and solidifies thereon to form the unnecessary resin wall 11 extending from a fringe portion 10a of the lower part 10 over the terminals 2′. In the case of the unnecessary resin wall 11 shown in FIG. 5, when the dissolved resin 8 injected into the molding space formed between the upper and lower molds 6 and 7 solidifies to form upper and lower parts 9 and 10 of the module electronic device in a body, the dissolved resin 8 rises to be higher than the terminals 2′ in close vicinity of the terminals 2′ and solidifies thereat to form the fringe portion 10a of the lower part 10 to be higher than the terminals 2′ so that a top of the fringe portion 10a forms the unnecessary resin wall 11.
The unnecessary resin wall 11 as shown in FIG. 4 or FIG. 5, especially, the unnecessary resin wall 11 as shown in FIG. 5, is unavoidably formed even in the condition in which the processing accuracy of each of the upper and lower molds 6 and 7 and the base board 3′ is improved to be respectably high.
When the module electronic device with the unnecessary resin wall 11 as shown in FIG. 4 or FIG. 5 is coupled with or removed from a connector 19 provided on an electronic apparatus, contacts 19a of the connector 19 come into contact with the unnecessary resin wall 11 to slide over the same and thereby the surface of the unnecessary resin wall 11 is shaved off by the contacts 19a to produce a resin powder P, as shown in FIG. 6. The resin powder P thus produced is put on the terminals 2′ and likely to injure a layer of surface treatment provided on each of the contacts 19a and the terminals 2′ and come to be put between the contacts 19a and terminals 2′ for preventing the contacts 19a from being in electrical contact with the terminals 2′. When the contacts 19a are prevented by the resin powder P from being in electrical contact with the terminals 2′, the module electronic device having the base board 3′ on which the terminals 2′ are arranged is not correctly connected with the electronic apparatus having the connector 19.
Accordingly, it is an object of the invention claimed in each of the claims of the present invention to provide a method for molding module electronic devices each capable of being easily coupled with and removed from a connector provided on an electronic apparatus to be used for an information recording medium of the card type or the like, with which the module electronic device can be obtained as a resin-molding without an unnecessary resin wall which is formed on or in close vicinity of terminals thereof and likely to prevent the module electronic device from being correctly coupled with the electronic apparatus, an apparatus for molding on which the method is carried out and a module electronic device molded by the method.